Unqualified Page Contexts (first, right)A margin declaration within a page context which is not qualified by a pseudo-class (or, for css3, a named page identifier) sets the margins for every page of the document which doesn't match a page context with a :first, :right, or :left pseudoclass (or, for css3, a named page identifier).

Unqualified Page Contexts (first, left)A margin declaration within a page context which is not qualified by a pseudo-class (or, for css3, a named page identifier) sets the margins for every page of the document which doesn't match a page context with a :first, :right, or :left pseudoclass (or, for css3, a named page identifier).

Right and Left Pages (page area equal)The right and left pages of a document may use differing margin styles that yield different page area widths, but the UA may adjust the margins such that the page area widths are the same.